This application claims the priority of Swiss Application No. 2000 0399/00 filed Mar. 01, 2000, which is incorporated herein by reference.
This invention relates to a shedding device for weaving machines whose warp threads guided in heddles between an upper shed position and a lower shed position are moved back and forth, whereby tension springs to return the heddles to the lower shed position move axially in a surrounding casing and grip each heddle, and the tension springs are attached to a downward-pulling base or rod of a downward-pulling frame.
Relevant shedding devices include so-called Jacquard machines in which the bottom end of two hooks are connected via a common pulley, whereby the hooks can be coupled to two stroke measuring devices that continuously move in the opposite direction depending upon the means of control, e.g. by magnetic means, whereby the heddles, e.g. suspended on the pulley, and hence the relevant warp threads are provided with a controlled stroke movement between the top shed position and bottom shed position. To return the heddles into the bottom shed position, a tension spring grips each heddle that is attached to a downward pulling base or downward-pulling rods of a downwardpulling frame.
A familiar problem with such machines is the accumulation of dust and fluff on the return springs which can quickly cause problems and requires long machine downtimes to eliminate the problem. It has been attempted to solve the problem by surrounding the tension springs gripping the heddles with a sleeve in which the relevant return springs move in an axial direction; however, this cannot prevent dust and fluff from penetrating the sleeves from the open face and clogging the return spring. The caps that are used in this context are also ineffective.
The object of the present invention is therefore to create a system that effectively prevents the collection of dust and fluff on the return springs to essentially eliminate downtime arising from such problems.
This object is attained according to the invention by placing a device to prevent dust and fluff from collecting on the return spring at the face of the sleeve that moves axially relative to the affected heddle.
Preferably, the device to prevent dust and fluff from collecting on the return spring can be a hermetically sealing lip seal surrounding the relevant heddle and/or hook or connecting means that sits tightly on the face or end of the sleeve.
It is advantageous for the lip seal to be exchangeable in a cage or the face of the sleeve or directly insertable in the cage. The lip seal acts as a dust or fluff remover on the heddle and/or hook or connecting means.
It is preferable for the lip seal to be a micro-lip ring seal.
These measures provide an optimum means for keeping the return springs clean with a relatively simple construction, and also prevent existing shedding devices of the cited kind to be retrofitted as desired independent of the fixed connection between the heddle or hook or connecting means and sleeve on the warp side or downward-pulling base side. The lip seal lies at the face where the sleeve moves axially relative to the affected heddle.